Public safety communications (PSCs) are critically important to save lives, property, and national infrastructure in case of incidents such as fires, terrorist attacks, or natural disasters. Until recently, PSC has been handled through narrowband communication technologies such as land mobile radio (LMR). Narrowband communication technologies can deliver reliable voice communications, but do not support broadband data and are also often limited in terms of coverage and interoperability. The National Broadband Plan by the FCC states that a cutting-edge PSC shall make use of broadband technologies “to allow first responders anywhere in the nation to send and receive critical voice, video and data to save lives, reduce injuries and prevent acts of crime and terror,” while acknowledging that “the U.S. has not yet realized the potential of broadband to enhance public safety” [1].
Broadband wireless technologies such as the 4G Long Term Evolution (LTE) and its 5G successor have a strong potential for revolutionizing communications during public safety situations. Driven by the need to meet the exponential increase in the demand for the wireless spectrum, research and standardization activities for 5G wireless networks are already underway, with an ambitious goal of 1000× capacity enhancement, 10× cell-edge user rate enhancement, and a 10× (to 1 ms) roundtrip latency reduction over 4G systems.
An important opportunity for revolutionizing PSC capabilities is to introduce unmanned aerial vehicles (UAVs), such as balloons, quadcopters, or gliders, for delivering pervasive broadband connectivity. Enabled by recent technological advances, miniaturization, and open-source hardware/software initiatives, UAVs have found several key applications recently. Amazon®, for example, is investigating using UAVs for rapid package delivery. Google® and Facebook® have been investigating the use of a network of high-altitude balloons and drones over specific population centers for providing broadband connectivity. Such solar-powered drones are capable of flying several years without refueling.
A relatively less explored application of UAVs is to deliver broadband data rates in emergency and public safety situations through low-altitude platforms [2]. UAVs are well-suited for such PSC scenarios due to their mobility and self-organization capabilities, which are valuable for quickly delivering broadband connectivity at times and locations where most needed, through an agile, low cost, and ubiquitous communication infrastructure.